Reactive distillation with multiple reactive sections for the energy-efficient synthesis of triethyl citrate: process integration and optimization

Abstract

Reactive distillation is a highly efficient process intensification technique, particularly suitable for reversible reactions. However, in the case of multi-step reversible reactions, mismatched reaction rates often result in low selectivity of intermediate products. This research proposes a reactive distillation approach with multiple reactive sections to address this challenge by incorporating an intermediate section within the reaction section. Using the synthesis of triethyl citrate as a case study, a reactive distillation with multiple reactive sections is designed, with process parameters optimized to minimize the total annual cost (TAC). Furthermore, a heat integration strategy is implemented, significantly reducing energy consumption. Compared to the reactive distillation with a single reaction section (RDC-SRS), the TAC is reduced by 7.5 % and 16.5 %, while the thermodynamic efficiencies are 13.82 % and 31.45 %, respectively. This configuration effectively decouples competing reactions, enhancing the selectivity of intermediate products. This work showcases multiple reactive sections of reactive distillation’s potential for complex, multi-step reversible reactions, offering insights into designing and optimizing sustainable, energy-efficient industrial processes.